Solar phenomena such as flares and solar energetic particles events are potential candidates to affect the global atmospheric electric circuit. One can study these effects using measurements of the atmospheric electric field in fair weather regions. In this paper, we investigate deviations of the atmospheric electric field daily curve during solar disturbances (solar flares and solar proton events) from mean values obtained in fair weather conditions. Using the superposed epoch analysis, in order to enhance the visualization of small effects, we study the atmospheric electric field data observed between January 2010 and December 2015 at the Complejo Astronómico El Leoncito, San Juan, Argentina. The results show no deviation of the atmospheric electric field after solar flares, and an increase of about 10 V/m after solar proton events. The last result suggests possible ionization effects above thunderstorm in disturbed weather regions, which alters the global atmospheric electric circuit. On the other hand, we analyze the variation of the atmospheric electric field during a ground level enhancement on 17 May 2012, which was capable to produce changes on the surface electric field.